Soldering iron



April 24, 1928. 1,667,618

C. C. ABBOTT SOLDERING IRON Filed Jan. 8. 1924 I Ff g. l.

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sommarnc morn Application Med. January My' invention relates tosoldering irons and has for its object the provision o\w special workingtip for soldering irons hereby the life of the iron is lengthened.

Soldering irons are ordin rily made of copper since this material hasthe high heat conductivity which is necessary for eflicient operation ofthe iron. Copper, however, has

the disadvantage that it is ra idly eaten away by the soldering flux orlaci and otherwise wears away rapidly. In carrying out my invention, Iprovide a special working tip on the soldering copper which tip iscomposed mainly 9f copper, whereby it has a satisfactory heatconductivity, and contains other metals making it resistaht .to acid andwear whereby the life of tllie soldering copper is materiallylengthenec.

For a more complete understanding of my invention, reference should behad to the accompanying drawing. in which Fig. 1 is a view partially insectlo'n of an electric soldering iron embodying my invention; whileFigs. 2, 3, 4 and 5 are views showing-var ious modifications of myinvention.

Referring to- Fig. 1 of the drawing, I have shown my invention in oneform as applied to an electrically heated'soldering iron although itobviously has a plication t0 va- .rious otherftypes of'sold ring irons..As shown, the soldering copper consists of an in.-

ner mass 10 of copper encased in a relatively" thin'outer protectingsheath 11, made of a suitable material which has'good heat Conductivitand which is resistant. to, these dering ux or acid. I have found that-an alloy containing approximately 64% copper, 21% zinc, 13% nickel, 1%%iron and a-fsmall amount of chromium is a very satisfactory material-for this purpose. While mismaterial does notconduct heat aseficientlyas copper, I have found that b mal ri ng' the sheath 11relatively thin as own,".=heat is conducted through it to the taperedwar n t such rate that the working" ciency of the iron is highlsatisfactory 1mder ordinary conditions 0 operation. The sheath 11 issecured to the co per mass 10 b means of a brazed or welde oint 12 whicextends over the tapered portion 01 the tip and back for a shortdistance whereby the sheath is. secured in good heat conducting relationwith the copper mass 10in the vicinity of the working surface so -thatheat is a, 1924;."- semi 10. cancer."

rapidly and efficiently conducted to the sheath; Thisrbrazed oint is notrequired along the body 13 of the soldering iron remote from the workings'urfacesince a largetion of the heat is available for conduction to theworkin surface. The protecting sheathll may e removed and renewed ifdesired by heating to; ii -temperature high enough to fuse the brazingmaterial.

As shown, the soldering copper is electrically heated, thecopper mass 10being provided with a bore 14 in which a suitable heating unit 15, shownas a cartridge type, is inserted. -.A thinsleeve 16 made of. a heatresisting material, such as a nickel chromium alloy, is rovided betweenthe heating unit 15 and t e mass 10. The pur ose of this sleeve 16 isto' ermit the removaFof the heating unit since have found that withoutthe sleeve,.the heating-unit as. a tendencyto 'freeze or adhere tothebeen used for a short-time.- Preferably, the heating unitpro'ectsiirom the bore 14 for a short distance or urpose of preventing.overheating of the 'erminals 17 and 18 ment of a. coiled w re handlesuch, for examass 10 after itthas of the heating unit and. also topermit its being grasped to -'pull it out-.- It will. be un- 1s,providedlrwith groove. 19' for the attachand the sheath around the bodyportion so ple, as disclosed United States Patent No.

' 957 ,256 to Edwin W, Rice, Jr. dated May 10,

Itw ill be observed that heat is conducted from the hea't'mg'j unit -15through the. co Hper mass "10- of igh heat conductivity irectly' to i, eof the soldereiipgi copper where it-is tran erred to the sh t 11 andconducted through this relatively thin sheath to the workingsurfaee.Under; similar con ditions of service, I have found that where theaverage life of an ordinary soldering copper isa'pproximately 60 days,the average lifeof :9 soldering copper provided with the protectingsheath of alloy is one year. Under these conditions the, copper ti mustbe retinned every 'dayand reshape every no v three days, while the tipmade of alloy in accordance with my invention'need be retinned' onlyonce each month and reshaped every six months.

In the modified form of my invention shown in Fig. 2, the protectingsheath 20 is applied only to the tapered portion of the solderingcopper; i. e., to the portion receiving the wear. -The sheath or tip 20is screwed on the reduced end 21 of the copper mass 22, the end 21 beingprovided with threads to receive the tip. When screwing the tip inplace, a small amount of silver solder is preferably placed in it andthe tip connected after heating both the tip and the mass 22 to atemperature high'enough to melt the silver solder. A soldered joint isthusformed whereby the two'parts are secured in good thermal relation.In case the soldering iron is heated during service to a temperaturehigh enough to melt the silver solder, the protecting sheath 20 will beheld in place by the threaded jointfand upon cooling, the silver solderwill solidify again. This tip may be easily removed and renewed ifnecessary by heating the iron to a temperature high enough to fuse thesilver solder.

In the modified form shown in.Fig. 3 a wear resisting tip made of alloyis provided in the form of arod 23 which is inserted in a central, bore24 in the copper. mass 25 and brazed or welded in place. As the workingsurface formed by the rod 23 wears away, it can be renewed by heatingthe soldering copper to ,a temperature high enough to melt the blazingmaterial and then pushing the rod out slightly after which the exposedend is reshaped. This form, and also the forms shown in Figs. 4 and 5has the copper is provided to conducttheheat to the working tip of alloymetal.

The modifications shown in Figs. 4 and 5 are somewhat similar. In theform shown in Fig.4, the tapered portion of the copper -31 of the alloymetal is placed and secured mass 26 is provided with two oppositely dis-I by brazing. The tip of alloy metal may be renewed in both of the formsshown in Figs. 4 and 5 by simply heating the soldering copper to atemperature high enough to'fuse the brazing material.

While I have described my invention as embodied in concrete form and asoperating in a specific manner in accordance with the provisions of thepatent statutes, It should be understood that I do not limit myvinvention thereto, since various modifications thereof will suggestthemselves to those skilled in the art without departing from the spiritof my invention, the scope of which is set forth in the annexedclaims.

What I claim as new and desireto secure by Letters Patent of the UnitedStates, is

1. A soldering iron comprising a mass of copper, a protecting sheath forsaid mass provided with a Working surface, and a soldered joint betweensaid sheath and said mass in the vicinity of said working surface, saidsheath fitting loosely over the remaining portion of said mass so as toprovide an air space to obstruct the transfer of heat therefrom.

2. The combination with a solderin .copper of a relatively thinprotecting s eath fitting loosely over said soldering copper so as toprovide an air space around said soldering :copper to obstruct thetransfer of heat therefrom, said sheath being provided with a workingsurface,and a soldered joint between said sheath and said solderingcopper in the vicinity of said working surface whereby heat is conductedfreely from said mass to said working surface.

' In witness whereof, I have hereunto set my hand this 3rd day ofJanuary, 1924;. CHARLES C. ABBOTT.

